At present, modes of liquid crystal display mainly include a Twisted Nematic mode, a Vertical Alignment mode, an In-Plane Switching (IPS) mode and an Advanced Super Dimension Switching (ADS) mode. A thin film transistor liquid crystal display of the ADS mode forms a multi-dimensional electric field between a slit electrode layer and a plate electrode layer through the electric field generated by an edge of a slit electrode in the same plane, so that between the slit electrodes in a liquid crystal cell and all oriented liquid crystal molecules directly above the electrodes are able to rotate, thereby improving the liquid crystal working efficiency and increasing the light transmittance. Therefore, the ADS technology can improve the picture quality of thin film transistor liquid crystal display products. In addition, the ADS technology also has the advantages of high resolution, high transmittance, low power consumption, wide viewing angle, high aperture ratio, low chromatic aberration and no squeezing water ripples. For this reason, it has more and more drawn people's attention and favour.
However, there are birefringence phenomena in the thin-film transistor liquid crystal display of the ADS mode and the thin-film transistor liquid crystal display of the IPS mode due to their material properties, for example. Birefringence may cause optical retardation in LCDs, and the optical retardation may lead to dark-state light leakage. When a frame of the backlight module of the thin film transistor liquid crystal display of these modes is deformed, a small gap between the frame and a display panel is inclined to cause the display panel to be squeezed. At the same time, a large gap (about 5˜10 mm) between the display panel and an optical film is inclined to cause the display panel to bend and deform. These factors can aggravate the birefringence phenomenon of LCD.
Therefore, how to reduce the dark-state light leakage of the liquid crystal display has become a technical problem to be solved in the present disclosure.